Intra-crystalline mesoporous SAPO-11 prepared by a grinding synthesis method as FCC promoters to increase iso-paraffin of gasoline

A hierarchical SAPO-11 was prepared by a grinding synthesis method (GSM) and added as a promoter to increase the iso-paraffin yield of gasoline in fluid catalytic cracking (FCC) reaction. Compared to the classical hydrothermal method , the GSM leads to the creation of intra-crystalline mesopores with the assistance of a surfactant (Cetyltrimethyl Ammonium Bromide, CTAB). CTAB acts as a structure directing agent and as a hard template during the crystallization of SAPO-11. CTAB micelles formed the intra-crystalline mesopores in SAPO-11 crystals. The intra-crystalline mesoporosity of the SAPO-11 is preserved at 800 °C under steaming, which renders the material as an appropriate component of the FCC catalyst. Besides, the presence of mesopores provides isomerization active sites and accelerates the desorption of iso-paraffin. The mesoporous SAPO-11 showed a higher selectivity for iso-paraffin and the yield of iso-paraffin increased by 2%.